Layered stent

ABSTRACT

The invention concerns a stent 1 for the bracing and/or holding-open of a body cavity having a tube 2 made from an elastic material, a tubular weave 3 comprising filaments 5 seating in close adjacency to the outer surface of the tube 2 as well as a coating 4 applied to the outer surface of the tube 2 which attaches the weave 3 to the outer surface of the tube 2. The coating 4 is adapted to have a structured outer surface dominated by the weave 3. The stent 1 in accordance with the invention can be produced economically with adjustable restoring forces and facilitates a secure placing within the body cavity. Means for preventing drifting within the body cavity can also be introduced onto outer surface of the stent.

BACKGROUND OF THE INVENTION

The invention concerns a stent for the splinting and/or holding-open ofa body cavity, in particular, an organ cavity.

DE 176 69 21 describes a stent configuration for the splinting andholding-open of a body cavity. The conventional configuration has atubular self-expanding network made from a plurality of mutually wovenfilaments. In accordance with an embodiment of DE 176 6921, the stent isconfigured as a reinforced tube, wherein the network is firmly embeddedwithin the tube. In the event that the tube is fashioned from a materialwhich is gentle to tissue, for example made from a plastic, a stentdevice which is suitable for splinting or holding-open of an organcavity results. Since the network is completely embedded within thewalls of the tube, the outer surface of the tube is smooth and thereforegentle to tissue if the tube is made from a material which is likewisegentle to tissue. However, the tube can become displaced relative to apredetermined position within the organ cavity.

In contrast thereto, it is the purpose of the present invention topresent a stent of the above mentioned kind which is economical toproduce and which facilitates a secure location within an organ cavityor body cavity, which is gentle to tissue, and which facilitates apermanent and stable positioning.

SUMMARY OF THE INVENTION

This purpose is achieved with a stent having a tube made from elasticmaterial, a tubular weave made from filaments firmly seating on theouter surface of the tube, and a coating covering both the weave as wellas the outer surface of the tube and holding the weave on the outersurface of the tube, the coating having a structured outer surfacedominated by the weave, wherein the diameter of the filaments formingthe weave is larger than the thickness of the coating.

The formation of the stent in accordance with the invention as acomposite product among three components having an inner tube, a tubularweave securely seated thereon and a coating disposed on the outersurface of the tube guarantees the production of a stent which is notonly economical to manufacture but also facilitates a gentle and securelocation within e.g. an organ cavity. The outer coating serves forfixing the weave on the outer surface of the tube, wherein the restoringforces (expansion of the stent from an elongated tensioned stent havinga smaller diameter into a state of the stent having a larger diameterand therefore an enlarged lumen) is determined by the cooperationbetween the elastic properties of the tube and the weave. The coating isconfigured in such a fashion that a structured outer surface of thestent results which is dominated by the structure of the weave. In thismanner, in contrast to the conventional stent, the stent in accordancewith the invention has a structured surface which guarantees a secureholding within the body cavity. The choice of material for the stent, inparticular material of the weave, can be used to adjust the restoringforces of the stent. In this manner, a more economical stent is producedwhich nevertheless guarantees secure location within the body cavity.The coating is kept sufficiently thin so that the structure of thefilaments leads to a corrugated surface for the stent in individualareal sections. This structured surface improves secure location andholding of the stent permanently in position within the body cavity.

Further advantages result when the weave is self-expanding. In thismanner, the restoring forces of the stent can also be adjusted throughchoice of a suitable weave and do not only result from the materialproperties of the tube.

In a preferred embodiment of the invention, the filaments have a roundcross section. This measure has the advantage that conventional wirematerial can be used as filaments forming a weave. In addition, thesimple structuring caused by a filament having a rounded cross sectionis sufficient to give a stent a prominent surface structure.

It is advantageous when the filament comprises polyester, kevlar, fiberglass, and/or metal or is made from such material. Polyester has theadvantage that it is a well-known material having good processingcharacteristics and is suitable for creating a stable joining of thetube and the coating. The choice of filament material, for examplepolyester or kevlar influences the restoring forces of the stent. Forexample, kevlar is stiffer than polyester and serves to create a stentwith stronger restoring forces. Use of fiber glass further expandspossibilities for adjusting the restoring force. Metallic filaments leadto strongly reenforced stent structures and facilitate positioning andlocating using X-ray investigations.

In an improvement in this embodiment, the filaments contain a mixture offiber glass and metal. This measure has the advantage that the restoringforces can be adjusted while simultaneously allowing the position of thestent to be checked using X-ray radiation.

It is, in general, advantageous if the filaments are impervious toX-rays. This has the advantage that, independent of whether or not therestoring forces are defined by polyester, kevlar or metal, it isnevertheless possible to check the location of the stent using X-rayradiation.

In an advantageous improvement of this embodiment, the metallic powderor metallic pieces, for example of tungsten, are in the tube or in thecoating. This measure has the advantage that the stent becomes "visible"through X-ray investigations not only when the filaments e.g. are madefrom metal, but also through metallic pieces imbedded into the stent toachieve an improved imperviousness to X-rays. In this manner, the choiceof filament material can influence the restoring forces of the stent inan expanded final state and, independent thereof, the placing of thestent can be checked using X-ray radiation.

It is particularly advantageous when the tube and/or the coatingincludes silicon. This has the advantage that silicon is a particularlysimple material to work and has properties which are gentle to tissue.

It is advantageous when the filaments have firmly fixed, protected ends.This has the advantage that filament ends cannot damage the tissue of abody cavity and that the structural stability of the stent in the endregions is improved in a defined manner. The weave can not fan out inthe outer region.

In an improvement in this embodiment, the neighbouring filament ends arepairwise connected to each other. This has the advantage that thefilament ends are captured and can not spread out freely.

In a particular embodiment of this improvement, the neighboring filamentends are connected to each other by means of a covering cap. Thiscovering cap can be a tube or cover-like object. This has the advantagethat a relatively simple mechanical construction, namely the coveringcap, leads to reliable protection and localization of the filament ends.

In another embodiment of this improvement, the neighbouring filamentends are each captured within a common filament tube. The tube protectsthe ends of the filament and holds the ends of at least two filamentstogether.

It is, however, also possible to weld the filament ends together e.g.using ultrasound welding. This measure has the advantage that noadditional material is necessary to guarantee a secure localization andprotection of the filament ends.

It is also possible to firmly glue the filament ends to the silicon tubeand to secure their location with a silicon coating (film). The crossingpoints at the ends can be knotted or wrapped using e.g. a silk thread.The combination of the inner tube and the covering cap has the advantagethat the ends do not become loose when the stent is stretched. It isalso possible to mark the ends with color to improve recognition of thestent ends when the stent is in the body. The inner surfaces of thestent can be structured in such a manner that a good and permanentmoistening and transport of fluid and/or cell tissue is possible.

The tube preferentially has a fold-over extending over the filamentends. This has the advantage that the tube and the filament endscooperate to captured the filament ends without having to produceadditional material connections.

In a preferred embodiment, the stent has raised sections protrudingbeyond the structured outer surface.

This has the advantage that the stent, in addition to the structuredouter surface, has means which guarantee an additional stationarypositioning of the stent in the body cavity. The raised portions can bearbitrarily distributed over the outer peripheral surface of the stentand push over an area into the neightoring tissue or become anchoredtherein so that the position of the stent is additionally secured.

In an additional configuration of the invention, the raised portions areformed by free ends of filament pieces which are at least sectionwiseproximate or parallel to the filaments forming the weave.

This has the advantage that, in order to produce such raised portions,only a single second filament thread is necessary which e.g. can extendparallel to the filament threads building the weave. This secondfilament thread should not influence the weave structure or stabilityand is separated after the desired sectional length is achieved. Theresulting free ends are bent to protrude beyond the outer surface of thestent so that an outer surface is produced having a plurality of hookswhich can penetrate into the surrounding tissue.

In an additional configuration of the stent in accordance with theinvention, the raised portions are formed by anchors which, in theelongated state of the stent, seat flatly on the outer surface of thestent with a first end being attached in a position-stable fashion tothe outer surface of the stent and a second free end, in an expandedstate of the stent, being separated from the outer surface of the stent.

This has the advantage that such an anchor can also be fashionedretroactively on a structured outer surface of a stent. The anchorsunfold when the stent is expanded and thereby penetrate into thebordering tissue. In the elongated state of a stent these anchors areflat at the outer surface of a stent so that placement of the stent isnot rendered more difficult by means of these anchors.

In an additional embodiment of a stent in accordance with the invention,the filaments forming the weave have differing separations from eachother and/or the filaments have differing diameters.

Variation of the type of weave and/or the grid size as well as of thethicknesses of the individual filament threads allows for adjustment ofvarious restoring forces in a stent so that, in dependance on the sizeand properties of a position in a body cavity, the most suitable stentcan be chosen. This stent therefore has a desired lumen expansion in theassociated body cavity which is secured in a permanent fashion to ruleout an unintentional migration of the stent.

In an additional embodiment the stent weave has differing contours in anaxial and/or radial direction so that the adjustment force within thestent can be additionally varied in dependance on the axial position.Differing shapes of the weave can be produced using thermal deformation.

It is particularly advantageous when the stent is configured in such afashion that it can be introduced into a body cavity using anapplication device. This has the is advantage that placement of thestent is simplified and reproduceable methods can be developed forplacing the stent in accordance with the invention.

In an improvement of this embodiment, the application device has acapture and displacement device as well as an application bushing and aconical plug. This has the advantage that the stent is not onlyintroduced into a body cavity using this application device, rather canalso be positioned using this device. The conical plug serves forsimplified handling in the application bushing.

In an improvement of this embodiment the capturing and displacementdevice has a spread-out capture basket made from a plastic or metallicweave. This has the advantage that the capture and displacement devicecan securely capture the stent and, after the stent is held foldedtogether within the application bushing, can free same. The capture anddisplacement device is configured and dimensioned in such a manner thatit can be displaced into the lumen of the application bushing.

If silicon is worked into the weave of the capturing basket, thecapturing basket can slide easily against the surface of applicationbushing and/or of the stent. Coatings made from teflon or polyethylenealso reduce friction. This guarantees a secure and simplified removal ofthe capture and displacement device from the stent which it engages.

It is advantageous when the capture and displacement device has a lumen.This has the advantage that the lumen of the capture and displacementdevice is suitable to guarantee observation of placement of the stentwithin a body cavity using optical means.

In an advantageous improvement, the capture and displacement devicesupports the stent when a section of the free end of the displacementdevice projects into the stent lumen. Small stent sizes <10 mm innerdiameter can not be damaged during displacement out of the applicationbushing, since they are supported from the inside. An additionalutilization of lubricant in the outer region of the stent is possible sothat the friction between the inner surface of the application bushingand the outer surface of the stent is reduced.

In order to separate the stent from the capturing basket, the stent isnot completely pulled into the application bushing. A conical plug isthen used to fix the stent in the application bushing and the capturebasket is pulled out. The protruding weaving can then be gentlyintroduced into the application bushing e.g. with the assistance of theback side of the conical plug. If the conical plug were not used,deformation of and damage to the stent, in particular with sizes lessthan 10 mm inner diameter, could occur.

The capture device and application bushing can be fashioned in such amanner that both objects can be produced with low wall thicknesses. Theapplication bushing then has a wall thickness which is sufficiently thinthat it must be stabilized by the capture device.

The choice of materials can facilitate a very high degree offlexibility. This has the advantage that a secure and simpleimplantation of the stent is guaranteed in a manner which is gentle tosurrounding bodies.

The invention also provides a method for introducing the stent, whereinthe stent is pulled into the lumen of the application bushing using theconically widened end of the capture and displacement device, the stentis fixed using the conical plug within the lumen of the applicationbushing, the capture and displacement device is separated from the stentand pulled out of the lumen of the application bushing, the conical plugis separated from the application bushing, the capture and displacementdevice is reversed and inserted again into the lumen of the applicationbushing, optical means can be displaced through the lumen of the captureand displacement device, the application bushing is introduced into thehollow body, and the stent is pushed out of the application bushingusing the capture and displacement device and placed within the bodycavity. This has the advantage that the stent can be initially capturedwithin the application bushing and held in a collapsed state in a simplemanner using the application device. The capture and displacement deviceis not only used to pull the stent into the application bushing, ratheralso to push the stent out of the application bushing into the bodycavity. The capture and displacement device thereby has an end having acapture device and an opposite end adapted to displace the stent out ofthe application device and into the body cavity.

A method for the production of a stent in accordance with the inventionhas the following steps: the weave is introduced on the outer surface ofthe tube in a firmly seating fashion and, subsequent thereto, the tubeand the weave are dipped into a fluid, for example silicon. This fluidsolidifies and forms the coating.

All free ends of the weave can also be welded to each other andadditionally protected by means of a glue layer. If the glue layercontains barium sulfide, then the end of the stent generates X-rayshadows.

This has the advantage that the stent in accordance with the inventionis very simple to produce.

BRIEF DESCRIPTION OF THE DRAWING

Additional advantages of the invention result from the description andthe drawing. The above mentioned features and those to be describedfurther below can be utilized in accordance with the inventionindividually or collectively in arbitrary combination. The embodimentsshown and described are not to be considered exhaustive enumeration,rather have exemplary character only for illustrating the invention.

FIG. 1a shows a tube forming the basis of the stent;

FIG. 1b shows a weave forming the basis of the stent;

FIG. 1c shows a layer forming the basis of the stent in accordance withthe invention;

FIG. 1d is a schematic representation of the composition forming thestent in accordance with the invention comprising a tube, a weave and acoating;

FIG. 2 shows a schematic cross section or end view of the stent of theinvention in accordance with FIG. 1d;

FIG. 3a shows an embodiment in accordance with the invention ofcapturing free filament ends using a cover cap;

FIG. 3b shows an additional embodiment in accordance with the inventionof captured filament ends using a filament tube;

FIG. 3c shows an embodiment having welded filament ends;

FIG. 3d shows a folding-over of the tube to effect capture of thefilament ends;

FIG. 4a shows an application device for placing the stent in accordancewith the invention;

FIG. 4b shows an application device in accordance with

FIG. 4a having an inserted stent and conical plug;

FIG. 4c shows an application device having a capture and displacementdevice turned with respect to FIG. 4a;

FIG. 5 shows a stent having raised portions on the outer peripheralsurface formed by free ends of filament pieces;

FIG. 6 shows a stent having anchors introduced on the outer surface inthe extended state;

FIG. 7 shows a stent in accordance with FIG. 6 in an expanded state.

FIG. 8 shows a stent having differing surface contours in dependence onaxial and radial directions;

FIG. 9 shows a stent in an expanded state having widened lumens at eachfree end region.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The figures are, in part, highly schematic to emphasize the featurespertinent to the invention. The dimensions shown in the figures are onlyexemplary and are not to be taken to scale.

FIGS. 1a-1d illustrate the construction of the stent 1 in accordancewith the invention. The stent 1 consists essentially of a tube 2 (seeFIG. 1a) made from elastic material, a tubular weave 3 tightly seatingon the outer surface of the tube 2 (see FIG. 1b) and woven together froma plurality of filaments 5, as well as a coating 4 (FIG. 1c) introducedonto the outer surface of the tube 2. FIG. 1d shows the stent 1 in theconstructed state. The inner tube 2 has a smooth inner surface and isstrengthened through integration with the weaving 3 comprising thefilaments 5, wherein the tubular weaving 3 and the inner tube 2 arejoined by means of the coating 4. In accordance with FIG. 1d, thecoating 4 is constructed in such a fashion that the prominent structurecaused by the filaments 5 on the outer surface of the tube 2 projectsthrough the coating 4 to lead to a structured outer surface of thecoating 4.

FIG. 2 shows a schematic cross section or end view of the stent inaccordance with the invention. The inner tube 2 as well as the weave 3,comprising the filaments 5 and tightly seating on the outer surface ofthe inner tube 2, are bonded together by means of the relatively thincoating 4. In the embodiment in accordance with FIG. 2, the stent 1 hasa structured outer surface dominated by the filaments 5 of rounded crosssection on the outer surface of the tube 2. The coating 4 is therebysufficiently thin that the spaces between the filaments 5 are notcompletely filled-up, wherein the structure dominated by the filaments 5at the outer surface of the tube 2 is simply covered in a sealed fashionusing the coating 4.

The embodiments in accordance with FIGS. 3a-3d show different ways ofholding the filament ends 9 together. In FIG. 3a, the ends 9 of thefilaments 5 are connected to each other in a protected fashion using acover cap 6. In accordance with FIG. 3b, the ends 9 of the filaments 5are each connected to each other by means of a common filament tube 7.The free ends 9 of the filament 5 in accordance with FIG. 3c are heldtogether and captured by means of a weldment 8. In accordance with FIG.3d, it is also possible to capture the free ends of the filament 5 bymeans of a folding-over 20 of the inner tube 2.

FIGS. 4a and 4b show an application device 10 which is suitable forintroducing the stent 1 into a body cavity. The application device 10 inaccordance with FIGS. 4a and 4b consists essentially of an outerapplication bushing 15 as well as an inner capture and displacementdevice 11. The inner capture and displacement device 11 has a spread-outcapture device 12 at one end and is configured smoothly at the endopposite to the capture device 12. In addition, the capture anddisplacement device 11 has a lumen 14. In FIG. 4a, the stent 1 is pulledinto the application device 10 in the direction of arrow 21 using thespread-out end of the capture device 12. The outer diameter of thecapture and displacement device 11 is thereby dimensioned in such afashion that it can be displaced within a lumen 13 of the applicationbushing 15. In accordance with FIG. 4c, a stent 1 which is alreadycaptured using the capture and displacement device 11 is displaced inthe direction of arrow 22 out of the application bushing 15 andpositioned within a body cavity.

In order to utilize the application device in accordance with FIGS. 4a,4b and 4c, the stent is initially pulled into the application bushing 15in accordance with FIG. 4a by means of the spread-out end 12 of thecapture and displacement device 11. After the stent 1 is completelywithin the application bushing 15 in accordance with FIG. 4b, the stent1 is positioned within the lumen 13 of the application bushing 15 bymeans of the conical plug 16. A guided motion of the capture device 12in the direction of arrow 21 then frees the stent 1. The conical plug 16is removed from the application bushing 15 and the capture anddisplacement device 11 is pulled out of the application bushing 15,turned around and once more inserted into the application bushing 15 atits other end (see FIG. 4c). Optical observation of the placing of thestent 1 is facilitated by an instrument which can be guided through alumen 14. The application device 10 is subsequently placed and situatedwithin the body cavity through displacement of the capture anddisplacement device 11.

FIG. 5 shows a stent 50 which is formed from a tube 51, a weave 52 and acoating 53. In addition to filament threads 54 from which the weave 52is produced, a second filament thread 55 is adjacent to the threads 54and is interrupted in sections, the free ends 56 of which protrude abovethe weave 52 and the coating 53. The free ends 56 build hooks for tissueadjacent to the outer surface of the stent.

FIG. 6 shows another embodiment of a stent 60, in the elongated state,which has, a weave 62. Anchors 65 are introduced on a flat section ofouter surface 64 of the stent 66. Each anchor 65 is connected to theouter surface 64 of the stent 60 in a position-stable manner via firstend 66. A second end 67 seats on the outer surface 64 of the stent 60.The stent 60 is elongated in the direction of arrow 68.

FIG. 7 shows the stent 60 of FIG. 6 in an expanded state. The stent 60expands in the direction of arrow 71 so that an increased lumen 72results. During expansion, the second ends 67 of the anchors 65 "standup" and become separated from the outer surface 64. The second ends 67facilitate the hooking or digging of the anchors 65 of the stent 60 intoan adjacent surface.

FIG. 8 shows a stent 80 which likewise consists essentially of a tube81, a weave 82 and a coating 83. The shape of the stent 80 differs independence on its axial and radial dimensions. The stent 80 assumes adistended shape 84 in an expanded state. The distended shape 84 iseffected by weaving the weave 82 over a mould having this distendedcontour 84. The shape can be arbitrary and can be adjusted to theapplication. The distended shape 64 shown in FIG. 4 can be fashioned ina permanent manner using thermal shaping techniques.

FIG. 9 shows an additional embodiment of a stent 90, consistingessentially of a tube 91 supporting a weave 92 a covered by a coating93. As seen from the side, the outer shape of the stent 90 has a concavedependence 94 along its axial extent so that the stent 90 has free ends95, 96 which define a wider lumen in both end regions of the stent 90.The free ends 95, 96 can be reenforced by means of ring structures onthe outer surface of the stent 90. These ring structures can also beintroduced on arbitrary sections of the stent at the outer surfacethereof independent of the embodiment of FIG. 9.

The invention concerns a stent 1 for the bracing and/or holding-open ofa body cavity having a tube 2 made from an elastic material, a tubularweave 13 comprising filaments 5 seating in close adjacency to the outersurface of the tube 2 as well as a coating 4 applied to the outersurface of the tube 2 which attaches the weave 3 to the outer surface ofthe tube 2. The coating 4 is adapted to have a structured outer surfacedominated by the weave 3. The stent 1 in accordance with the inventioncan be produced economically with adjustable restoring forces andfacilitates a secure placing within a body cavity. Means for preventingdrifting within the body cavity can also be introduced onto the outersurface of the stent.

We claim:
 1. A stent system for the splitting and holding open of a bodycavity, the stent system having a stent comprising:a tube made from anelastic material; a tubular weave seating firmly on an outer surface ofsaid tube, said weave having a filament with a diameter and; a coatingcovering said tube and said weave to hold said weave on said tube, saidcoating having a thickness less than said filament diameter, saidcoating consisting essentially of a self-solidifying fluid into whichsaid tube and said weave are dipped, whereby the stent has a structuredouter surface defined by said weave, and further comprising anapplication device for introducing the stent into a body cavity, saidapplication device comprising a capture and a displacement device, anapplication bushing, and a conical plug.
 2. The stent of claim 1,wherein said weave is expanded.
 3. The stent of claim 1, wherein saidfilament has a rounded cross section.
 4. The stent of claim 1, whereinsaid filament comprises at least one of polyester, kevlar, fiber glassand metal.
 5. The stent of claim 1, wherein said filament is imperviousto x-rays.
 6. The stent of claim 1, wherein at least one of said tubeand said coating contain metal.
 7. The stent of claim 1, wherein atleast one of said tube and said coating contain silicon.
 8. The stent ofclaim 1, wherein said filament has a fixed end, and wherein saidfilament comprises a plurality of threads having neighboring endspair-wise welded to each other.
 9. The stent of claim 1, wherein saidweave has a shape produced by thermal shaping techniques.
 10. The stentof claim 1, wherein said capture and displacement device has asubstantially conical spread-out end.
 11. The stent of claim 1, whereinsaid capture and displacement device for displacement into a lumen ofsaid application bushing.
 12. The stent of claim 1, wherein said captureand displacement device has a lumen.
 13. A stent system for thesplitting and holding open of a body cavity, the stent system having astent comprising:a tube made from an elastic material; a tubular weaveseating firmly on an outer surface of said tube, said weave having afilament with a diameter and; a coating covering said tube and saidweave to hold said weave on said tube, said coating having a thicknessless than said filament diameter, said coating consisting essentially ofa self-solidifying fluid into which said tube and said weave are dipped,whereby the stent has a structured outer surface defined by said weave,wherein said filament has a fixed end, and wherein said filamentcomprises a plurality of threads having neighboring ends pair-wisesconnected to each other, and further comprising a covering element forpair-wise connecting said neighboring ends.
 14. The stent of claim 13,wherein said covering element comprises a covering cap pair-wiseconnecting said neighboring ends.
 15. The stent of claim 13, whereinsaid covering element comprises a filament tube capturing saidneighboring ends.
 16. The stent of claim 8, wherein said neighboringends are welded together.
 17. A stent system for the splitting andholding open of a body cavity, the stent system having a stentcomprising:a tube made from an elastic material; a tubular weave seatingfirmly on an outer surface of said tube, said weave having a filamentwith a diameter and; a coating covering said tube and said weave to holdsaid weave on said tube, said coating having a thickness less than saidfilament diameter, said coating consisting essentially of aself-solidifying fluid into which said tube and said weave are dipped,whereby the stent has a structured outer surface defined by said weave,and further comprising raised portions protruding beyond said structuredouter surface.
 18. The stent of claim 17, wherein said raised portionsconsist essentially of free ends of second filament pieces extendingproximate said filament.
 19. The stent of claim 9, wherein said raisedportions consist essentially of anchors which seat flatly on said outersurface of the stent in an elongated state of the stent and are firmlyattached in a fixed spatial location at a first end thereof to saidouter surface of the stent and which are separated from said outersurface of the stent at a second free end thereof in an expanded stateof the stent.
 20. A stent system for the splitting and holding open of abody cavity, the stent system having a stent comprising:a tube made froman elastic material; a tubular weave seating firmly on an outer surfaceof said tube, said weave having a filament with a diameter and; acoating covering said tube and said weave to hold said weave on saidtube, said coating having a thickness less than said filament diameter,said coating consisting essentially of a self-solidifying fluid intowhich said tube and said weave are dipped, whereby the stent has astructured outer surface defined by said weave, wherein said tube has afold-over covering an end of said filament.
 21. A stent system for thesplitting and holding open of a body cavity, the stent system having astent comprising:a tube made from an elastic material; a tubular weaveseating firmly on an outer surface of said tube, said weave having afilament with a diameter and; a coating covering said tube and saidweave to hold said weave on said tube, said coating having a thicknessless than said filament diameter, said coating consisting essentially ofa self-solidifying fluid into which said tube and said weave are dipped,whereby the stent has a structured outer surface defined by said weave,wherein said filament comprises a plurality of threads having at leastone of differing separations with respect to each other and differingdiameters.
 22. A stent system for the splitting and holding open of abody cavity, the stent system having a stent comprising:a tube made froman elastic material; a tubular weave seating firmly on an outer surfaceof said tube, said weave having a filament with a diameter and; acoating covering said tube and said weave to hold said weave on saidtube, said coating having a thickness less than said filament diameter,said coating consisting essentially of a self-solidifying fluid intowhich said tube and said weave are dipped, whereby the stent has astructured outer surface defined by said weave, wherein said weave hasshapes differing in at least one of an axial and a radial direction. 23.A method for introduction of a stent system into a body cavity, themethod comprising the steps of:a) pulling the stent into a lumen of anapplication bushing using a conically widening end of a capture anddisplacement device; b) fixing the stent within said lumen of saidapplication bushing using a conical plug; c) separating said capture anddisplacement device from the stent; d) pulling said capture anddisplacement device out of said lumen of said application bushing; e)separating said conical plug from said application bushing; f) turningaround said capture and displacement device; g) inserting said captureand displacement device once more into said lumen of said applicationbushing; h) displacing optical means through a lumen of said capture anddisplacement device; i) introducing said application bushing into thebody cavity; j) positioning the stent out of said application bushingand into the body cavity using said capture and displacement device.